The present invention relates to a device for activating a rotating post, especially one that moves a swinging-door panel in a motor vehicle, whereby the post, which is mounted in such a way that it can rotate in mounts at each end, is a hollow cylinder that accommodates a worm gear driven by a bi-directional pneumatic piston-and-cylinder drive with a piston rod that is attached to part of the worm gear and is positioned in such a way that it cannot rotate within a guide that is rigidly fastened to one of the mounts.
An activating device of this type is known for example from German Pat. No. 1 961 573. The piston-and-cylinder drive is located outside of and at one end of the rotating post and is connected to it by means of a worm gear inside the post.
The drawback of the known activating device is that it requires space above and below the rotating post to accommodate the piston-and-cylinder drive although the space at each end of the post is limited, especially in motor vehicles, such as buses for example.